Yangon back in 2012; Myanmar had only "reopened" for tourism a couple of years before and I read about people having issues at the airport. FWIW I was traveling solo as a 22 year old backpacker, and I had an issue both on entry and departure. Entry - I approached immigration and they almost immediately pulled me into a back room that looked and felt like airport jail. I had no idea why or what they were asking me about but after about 30 minutes I was stamped in and released. It was unsettling but nothing too bad, and a few people at my hostel said the same thing had happened to them.
Departure on the other hand... The entry stamp was very faint and they had put it practically right on top of another stamp. Even I could barely find it in my own passport, and low and behold when I got to immigration, the office cannot find it. It became a giant "how did you get into the country" thing, and I was taken to the same creepy back room for questioning. A US State Dep. agent came into the room after a little while and assisted and was able to get me out, through immigration and security and on my way. I always double check my entry stamps now.
The most thorough passport check I've had was at SVO. We left after they invaded Ukraine and ended up being on the last flight to the States. We had to transit at SVO and the immigration officer saw our Ukraine stamps from just a few months prior and proceeded to ask us all about that trip, why we would have gone to Ukraine, etc, as well as every other Baltic and eastern european stamp. It took forever and we were sweating, but it all worked out.